Improvement in dies for molding plastic substances



. M. GARTY. Dies for Molding Plastic Substances.

No. 200,986. Ptented March 5,1878.

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Lida/m6? UNITED STATES PATENT OFFICE.

MARTIN OARTY, OF NEWARK, NEW JERSEY.

IMPROVEMENT IN DIES FOR MOLDING PLASTIC SUBSTANCES.

Specification forming part of Letters Patent No. 200,986, dated March 5,1878 application filed July 25, 1877.

To all whom it may concern:

Be it known that I, MARTIN OARTY, of Newark, in the county of Essex andState of New Jersey, have invented a new and useful Improvement in Diesfor Molding Plastic and other Materials, such as india rubber,celluloid, and other like substances, which improvement is fully setforth in the following specification, reference being had to theaccompanying drawing, in which- Figure 1 represents a vertical centralsection. Fig. 2 is a horizontal section. Fig. 3 is a vertical sectionwith the hollow cap which is used for relieving the center plug of thefollower from pressure. Fig. 4is a detached perspective View of one ofthe sections of the die.

Similar letters indicate corresponding parts.

This invention consists in a die of any number of sections most suitableto produce the desired effect or pattern, which are fitted into asuitable receiver, each of the sections being provided with a cavity,and being retained in position by a screw, so that when the severalsections are secured in the receiver a continuous cavity is formed inthe die corresponding to the article to be molded, and after thematerial for such article has been pressed into said cavity the die canbe readily removed from the receiver, and by taking the same apart thefinished article drops out of the cavity, and rings or other articles,with designs or figures in relief, can be readily formed. With this dieis combined a follower containing a tapering center plug and a hollowcap, so that at the beginning of the pressing operation the material isforced into the cavity of the die, and then, by applying the hollow cap,the tapering center plug recedes and the surplus material passes intothe body of the follower.

In the drawing, the letter A designates my die, which is composed of anysuitable numder of sections, a b c,- which are fitted into the receiverB, and retained in position by screws d. In the interior of the die isformed a cavity, e, which corresponds in shape to the article to bemolded, such, for instance, as a ring, which may be plain or ornamentedby designs or characters of any desired form, such designs or charactersbeing engravedinto the interior surface of the cavity 0. By making thedie in sections, the labor of en gravin such designs or characters ismaterially facilitated by exposing the surface to be engraved fully tothe workman.

In the example shown in the drawing both the die and the receiver arecircular; but they may be made in any other suitable form or shape.

With the die and the receiver are combined a plug, (3, and a follower,D, which are adapted to meet at any given point most suitable to forcethe material into the cavity 6 of the pattern or die. After the plug 0has been inserted, a quantity of the material to be pressed is placedinto the die, the follower D is applied, and the whole is placed under apress. By applyin gpressure the material to be pressed is forced intothe cavity 6; but, in order to produce clean articles, it is requisitethat the follower shall be depressed, so that its inner surface shallmeet, as near as possible, the inner surface of the plug 0, as shown inFig. 3. The follower is provided with a head, f, by which it can beconveniently lifted out.

It is found, however, that in depressing the follower the surplusmaterial is squeezed out between the head f and the surface of the die,and in this case the follower cannot be depressed to the desired point,and the articles have not the proper finish. This difficulty I haveovercome by providing the follower D with a tapering plug, g. When thisplug is in position, as shown in Fig. 1, its inner surface is flush withthe inner surface of the follower, but its outer surface projects beyondthe outer surface of the follower, and, when pressure is applied to thefollower by means of a flat plate or platen, such pressure comes to bearon the outer end of the plug, and this plug is" depressed together withthe follower. After sufficient pressure has been applied to force thematerial into the cavity 6, I place on the top of the follower a hollowcap, E, Fig. 3, and then I complete the operation of pressing byapplying pressure on the cap. During this stage of the process the plug9 recedes and the surplus material passes up into the cavity previouslyoccupied by said plug, so so that the follower D can be depressed untilits inner surface comes in contact with the surface of the plug 0.

After the pressing operation has been completed, the plug C and thefollower D are taken out, the die is removed from the receiver, and bytaking said die apart the pressed article is caused to drop out of thecavity e without any danger of injuring its shape or the designs orcharacters with which the same may be ornamented.

My die can be used for pressing plastic materials of variousdescription, and also metallic alloys or other materials.

The same receiver and die can be used by giving to the sections of saiddie a radial motion, so that they can be compressed against a blankplaced on a center-pin. Each section of the die, in this case, is guidedby a pin radiating from the center-pin, and the screws d complete thepressure. This device, however,

forms the subject-matter of a separate application.

What I claim as new, and desire to secure by Letters Patent, is

1. A die composed of any suitable number of sections fitted into asuitable receiver, each of the sections being provided with a cavity andbeing retained in position by a screw, in combination with a plug, 0,and a follower, D, all constructed and adapted to operate substantiallyas herein shown and described.

2. The combination, with the follower D, die A, and receiver B, of atapering plug, g, and a hollow cap, E, substantially as and for thepurpose set forth.

In testimony that I claim the foregoing I have hereunto set my hand this24th day of July, 1877.

MARTIN CARTY. Witnesses:

W. HAU'FF, CHAS. WAHLERs.

